The 2010 healthcare law has generated multiple controversies, and some of them were unavoidable. For example, once lawmakers decided to require insurers to disregard preexisting conditions -- a reform that most people actually like -- they had to take other steps to avoid triggering a vicious spiral of premium increases. None of those steps would have been popular, although the route Congress chose (requiring virtually every adult American to buy insurance, then creating costly subsidies for those who couldn't afford to comply) may have been the path of most resistance.

Some of the controversies set off by the law, though, could have been avoided had Congress chosen a different approach to overhauling the healthcare system. A good example is the employer mandate, or the requirement that employers with more than 49 full-time workers provide comprehensive coverage to their employees at an affordable price.

Supporters of the mandate argued that it was necessary to stop companies from canceling their health benefits and dumping their employees into the subsidized state exchanges. But opponents say it discourages small companies from expanding, while giving employers an incentive to use more part-time workers who won't qualify for mandatory benefits. There's been plenty of anecdotal evidence of these effects, although federal employment statistics show that the ratio of part-time to full-time jobs is actually decreasing.

There's another argument against the employer mandate: that it ignores the market realities that led most larger employers to provide coverage before Congress enacted the Affordable Care Act. It's hard to recruit workers in a competitive market for talent if you don't offer health benefits. And any company that stops offering benefits will only guarantee that its most valuable workers run off to employers that continue to provide them, unless it offers wages high enough to cover the difference.

A report released Friday by the nonpartisan Robert Wood Johnson Foundation and the left-leaning Urban Institute supports that contention. Titled "Why Not Just Eliminate the Employer Mandate?," it finds that the law's requirement that larger employers insure their full-time workers will make almost no difference in the total number of Americans insured. In fact, the authors say that if the mandate were eliminated, "employers may play more of a role promoting the expansion of coverage under the law."

The report projects that canceling the mandate would cause employers to extend benefits to 500,000 fewer people than they do today, a reduction of 0.3%. Most of those people would obtain individual policies, often by purchasing subsidized plans through a state exchange, the report estimates. The bottom line: The number of insured Americans would be higher than before the ACA was adopted, but the total would be about 200,000 less than with the employer mandate.

Most employers would not drop coverage if the penalties were eliminated. About two-thirds of American workers now have offers of employer coverage when there is no mandate.— Authors of "Why Not Just Eliminate the Employer Mandate"

The authors assert that the vast majority of employers would continue to provide benefits without the mandate, in part because of the tax break Washington provides for them. That tax break makes it cheaper for companies to pay part of the cost of a health insurance plan than to give workers the extra salary needed to buy coverage on their own. Workers, who face tax penalties of their own if they don't have coverage, also will pressure their employers to offer health benefits.

Nevertheless, the report acknowledges that removing the mandate would cost taxpayers about $4.3 billion a year. The vast majority of that sum isn't new spending, though; it's lost revenue. The government expects to collect almost $4 billion in penalties from employers that don't comply with the mandate, and with no mandate, there would be no penalties.

On the other hand, companies will probably pass along those penalties to their customers or take them out of their workers' wages, so in that sense the money will still be coming from the public. And the Obama administration has yet to collect a dime in penalties because it has twicedelayed the mandate's effective date.

Lawmakers can't afford to undermine the employer-based coverage that extends to so many of their constituents. More than half of all Americans have health coverage through an employer, including nearly two-thirds of the adult workers who are too young to qualify for Medicare. As of 2012, the report says, 96% of all companies with at least 50 full-time workers provide a comprehensive health plan.

At the same time, Congress has to recognize how the mandate distorts employers' behavior, and not necessarily in a good way. And if the mandate remains in effect, it has to recognize who'll actually be penalized for not complying. According to the report, the companies most likely not to comply are the ones that don't offer benefits today, particularly those that pay at least half their workers at or near the minimum wage. As a consequence, the authors argue, "low-wage employees will bear the greatest brunt of the penalties imposed" if the mandate goes into effect.